However, why do you need the radio directly wired to the battery?
At bigger airports, you can spend ages (tens of minutes, even) waiting for them to call you back. Or just calling them over and over until they respond – Valencia was one such. This will drain your battery. My plane, with avionics ON, draws about 15A for a few mins and then (as the AHRS warms up) about 10A. The battery is only 15Ah…
Peter wrote:
I have had a bollocking for starting up without asking for a startup clearance, a number of times.It’s also a good reason to get the #1 radio wired directly to the battery (via a CB of course, and with 2 diodes so you don’t get current flowing the wrong way)
Oban required call for startup, for VFR. I have no idea why. (The fueller says he never bothers asking for it). It seemed like delusions of grandeur to me. The fueller reckoned that they had heard Loganair doing it once and thought “what a good idea” without actually thinking what its purpose was (no doubt Loganair do it because they don’t want to sit there idling burning absurd amounts of fuel while waiting for a clearance).
However, why do you need the radio directly wired to the battery? I just turned on the master and radio, booked out and asked for start all in one single call, turned the radio off for starting and cranked up and did my normal thing.
Also, the time you normally ask for a startup is after you have
Except the handheld radio doesn’t power your aircon, though 
A handheld radio solves all your “should I startup or not” ambiguities.
I have had a bollocking for starting up without asking for a startup clearance, a number of times.
It’s also a good excuse to ask for the departure clearance
It’s also a good reason to get the #1 radio wired directly to the battery (via a CB of course, and with 2 diodes so you don’t get current flowing the wrong way)
Solaris wrote:
i would have no qualms running the engine per se without startup clearance.
Seconded. You can always use the excuse that you need to run the engine for ground power (charge the battery etc).
Plus, the startup clearance thing is mostly for the benefit of those who pay (maintenance) by cycle and have a humongous idle fuel flow (i.e. turbines), it would be hard for them to power up their engine(s) just to be told they have a 2 hour slot…
I don’t know how the SAT24 tops colouring is generated.
Ideally it should be done by knowing the temps aloft (which are forecast with a reasonable accuracy) and converting the ex-EUMETSAT shades of grey into temps (which EUMETSAT gives you, because the shade of grey is directly the absolute temperature, and the satellite IR camera is calibrated for that) and then converting into altitudes.
However one Spanish site I recall (may have been the Univ of Granada one) used ISA temps for the altitude conversion, which is obviously useless!!
And this may be the problem with the SAT24 image. Computationally it is less than trivial to do it correctly because you need the GFS 3D data etc. I bet you they use ISA temps…
And that leads to a huge variation. In the summer one often sees ISA+15 which is an error of some 7000ft if you just use ISA temps for the colouring. And in the summer the tops will appear 7000ft lower than they really are, because they are warmer and will thus be depicted lower down… dangerous!
I have not previously heard of “IFR startup”. AIUI, ATC transmits a DEP message when you start taxi on a Eurocontrol-filed FP. (and probably for a VFR FP too, if it is a proper airport, otherwise VFR FPs are totally unmonitored until you land). If you fail to turn up at the airport by the EOBT, they transmit a NODEP or whatever it is called.
Peter wrote:
It sounds like you have your preflight process pretty well sorted. Very good work
well, i have to say that a certain peter2000 ’s trip reports greatly contributed to developing and enhancing pre- and in-flight processes… i would even say i am guilty of copyright infringement, blatant copy-paste.
Peter wrote:
Yes – quite often the IR image is misleading because it shows high altitude tops, say FL300. I think these can be detected by the rather “thin” patterns they form, and of course no sferics etc. It’s easier to see when you don’t have the coloured cloud top layer enabled.
i kind of like the “tops” image, immediately highlighting potentially critical areas. i will give it a try for suspected thin bands without though.
one thing about the “tops” image is, i think it consistently underestimates the tops by a large margin. for example on a flight on saturday from Biggin Hill to Basel the reported tops were much lower than in reality, and i don’t think there was enough vertical development for the rise to be justified. this is not the first time i am seeing this:
Peter wrote:
I too always request a startup clearance and a departure clearance, at any large-ish airport, because while some don’t care about the startup, others really do.
i believe that the IFR term “startup” is not directly tied to “engine startup”, but it is ATCs way of telling you that from startup you are expected to be ready for departure within 15 minutes (engine start, taxiing, power checks, briefing, all completed). it marks the beginning of the IFR systems’s timeline. while i usually work with the hand-radio up to startup / clearance, i would have no qualms running the engine per se without startup clearance.
Great report, very detailed, thank you 
It sounds like you have your preflight process pretty well sorted. Very good work
Yes – quite often the IR image is misleading because it shows high altitude tops, say FL300. I think these can be detected by the rather “thin” patterns they form, and of course no sferics etc. It’s easier to see when you don’t have the coloured cloud top layer enabled. Fortunately this situation is blindingly obvious when you are flying and approaching the relevant area.
IFR departures in UK Class G can be tricky because if you filed your FP for a too-low level, London Control might reject it and the departure clearance will be subtly different – the handover will be to some local unit, and this may not be obvious to a non-UK pilot. But if you filed for FL150 (looking at the enroute level in the GRAMET) that will work fine.
I too always request a startup clearance and a departure clearance, at any large-ish airport, because while some don’t care about the startup, others really do.
